A pressure-sensitive adhesive product is usually provided in a structure having a pressure-sensitive adhesive layer on a support or a type of a layer having pressure-sensitive adhesive layers on both surfaces thereof. In the pressure-sensitive adhesive product, when a pressure-sensitive adhesive surface is placed on an adherent surface and a certain pressure is applied, adhesion is induced.
For example, when at least two materials are attached using the pressure-sensitive adhesive product, ideally, both surfaces of the pressure-sensitive adhesive product necessarily have required physical properties, and in many cases, physical properties required for the both surfaces are different from each other. For example, when a glass base is attached to a polymer base, it may be suitable that one surface of the pressure-sensitive adhesive product has an affinity to the glass base, and the other surface of the pressure-sensitive adhesive product has an affinity to a polymer base.